use has_field for planning box rather try / except on get_field

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@6496 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/bootstrap/erp5_html_style/SkinTemplateItem/portal_skins/erp5_html_style/form_html.xml

@@ -118,7 +118,7 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.\n
          tal:attributes="href python: here.portal_url() + \'/\' + \'erp5_html.css\'" />\n
 \n
     <!-- taking \'planning_box\' in charge if exists -->\n
-    <tal:block tal:condition="exists: python:form.get_field(\'planning_box\')" tal:on-error="nothing">\n
+    <tal:block tal:condition="python:form.has_field(\'planning_box\')">\n
        <tal:block tal:define="planning_box1 python:form.get_field(\'planning_box\');dummy python:request.set(\'here\',here)" >\n
           <style tal:content="structure python: planning_box1.render_css(None,REQUEST=request)"/>\n
        </tal:block>\n

product/ERP5/bootstrap/erp5_html_style/SkinTemplateItem/portal_skins/erp5_html_style/view_master.xml

@@ -108,7 +108,7 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.\n
          tal:attributes="href python: here.portal_url() + \'/\' + \'erp5.css\'" />\n
 \n
 \n
-   <tal:block tal:condition="exists: python:form.get_field(\'planning_box\')" tal:on-error="nothing">\n
+   <tal:block tal:condition="python:form.has_field(\'planning_box\')">\n
       <tal:block tal:define="planning_box1 python:form.get_field(\'planning_box\');dummy python:request.set(\'here\',here)" >\n
         <style tal:content="structure python: planning_box1.render_css(None,REQUEST=request)"/>\n
       </tal:block>\n